Pivot irrigation system and components

ABSTRACT

In one example, a continuous track transport system for an irrigation system is provided that includes a continuous track with multiple track plates arranged so that adjacent plates are directly connected to each other, and also includes a gear train connected with the continuous track and operable to transmit an input torque to the continuous track to effect movement of the continuous track. The gear train includes a drive gear having an interface that is connectible to a gearbox of an irrigation system chassis, first and second driven sprocket-gears engaged with the continuous track, each of first and second driven sprocket-gears including a respective driven gear engaged with the drive gear, and a frame to which one or more gears of the gear train are rotatably mounted. Any one or more of the drive gear, sprocket-gear, and frame may comprise, or consist of, molded, glass-filled nylon.

RELATED APPLICATION

This application is a continuation-in-part (CIP) of, and hereby claimspriority to, U.S. patent application Ser. No. 14/532,555, entitled PIVOTIRRIGATION SYSTEM AND COMPONENTS, and filed on Nov. 4, 2014. Thisapplication also hereby claims priority to U.S. Provisional PatentApplication, Ser. 62/393,800, entitled TRACK FOR IRRIGATION SYSTEM, andfiled Sep. 13, 2016. All of the aforementioned applications areincorporated herein in their respective entireties by this reference.

FIELD OF THE INVENTION

The present disclosure is generally concerned with irrigation systemsand related components. At least some example embodiments are concernedwith pivot irrigation systems that include a continuous track transportsystem.

BACKGROUND

Irrigation systems are sometimes automated so that they can irrigatelarge fields, or portions of fields, largely without human action orintervention. To this end, such irrigation systems may include one ormore sets of tires that enable the irrigation system to be moved todifferent locations in the field that is being irrigated. Movement ofthe irrigation system may be performed by way of a drive system coupledto the tires.

While the one or more sets of tires enable the repositioning of theirrigation system, the use of tires can present a variety of problems.One such problem is that, due to the weight of an irrigation system,particularly when filled with water, as well as to the relatively largesize of the tires, the tires often make tracks in the soil of theirrigated field that are quite deep and/or wide. These tracks, which aresometimes referred to as pivot tracks, can make it quite difficult forother equipment, such as harvesters, trucks and tractors for example, totravel through the field.

As well, when one or more irrigation systems are moved, such tracks canmake it difficult, or impossible, for the wheels of other irrigationsystems to travel through the field. Moreover, these irrigation systemscan experience significant wear and tear as they attempt to navigatethrough and over the tracks left by another irrigation system.

Another example of problems presented by the use of tires in anirrigation system concerns the field itself. In particular, the trackscreated by such tires can cause soil erosion in the field. The erosioncan be aggravated further if the tire tracks become filled with waterand muddy, as commonly occurs.

A related problem is that the relatively wide configuration of the tiresresults in a corresponding reduction in the amount of field space thatis available for growing. Depending upon the size of the irrigationsystem, and number and size of associated tires, this reduction can bequite significant in some cases.

In addition to the problems noted above, the tires themselves areinherently prone to various problems. For example, the tires typicallyemployed in irrigation systems are pneumatic. Thus, the rubber tirematerial is prone to deterioration due to long exposure to the sun, andpneumatic tires may go flat as a result of valve failure or contact witha sharp object. Regardless of the failure mechanism, the tire then hasto be repaired or replaced, which may be time-consuming and expensive.For example, the repair or replacement of one or more tires introducesundesirable down time for the irrigation system. This down time can beparticularly problematic, for example, in hot weather conditions wherean adequate flow of water is critical to the survival of the crop.

Moreover, if a tire goes flat, a farmer may not become immediately awareof the problem and, as a result, the irrigation system may continue tooperate with the flat tire, or flat tires. This can put undue wear andtear on the irrigation system, including components of the drive systemsuch as linkages and bearings, as the irrigation system moves throughthe field.

Moreover, even if a tire does not go flat, problems can still occur. Forexample, if adequate pressure is not maintained in the tire, theperformance of the tire will suffer and it may be relatively moredifficult for the tire to move through the field than would be the caseif the tire were at the correct pressure. This problem can be aggravatedfurther by the condition of the field where the irrigation system isemployed.

As well, it should be apparent that when the foregoing problems occur inlarge growing operations that include numerous irrigation systems andassociated tires, these problems present a significant cumulative impacton time, productivity, and finances.

Some efforts to resolve problems such as those noted above involve theuse of a track that rotates around two pneumatic tires. Although such anarrangement may result in a somewhat less problematic track shape, thesearrangements introduce their own set of problems. For example, the useof pneumatic tires is problematic for the reasons already stated.

As well, because these track and tire arrangements may rely on a highlevel of track tension for useful operation, the use of equipment suchas tensioners is required. These tensioners however can imposetremendous stress on components such as shafts, bearings and gearboxes,thus reducing the useful life of those components. As well, thetensioners may be vulnerable to changes in tire pressure, such that thetension can vary with the tire pressure. Moreover, tire pressure canchange dramatically throughout the course of the day and performance ofthe track and tire arrangement will vary accordingly. A related problemis that there is no easy way for a farmer or other user to monitor, andeffect changes in tire pressure should there be a need to do so.

Finally, track and tire configurations that employ rubber tracks presentstill further problems. For example, rubber tracks can degrade afterprolonged exposure to sun and heat. Replacement of these rubber tracksintroduces further expense in the form of parts, labor, and irrigationsystem down time. Other problems with rubber tracks include high tracktension, which can cause bearing problems, and expense.

In light of problems such as these, it would be useful to have anirrigation system, such as a pivot irrigation system, for example, thatwas configured in such a way that at least some of the problemsassociated with the use of tires may be avoided.

BRIEF SUMMARY OF SOME ASPECTS OF THE DISCLOSURE

It should be noted that the embodiments disclosed herein do notconstitute an exhaustive summary of all possible embodiments, nor doesthis brief summary constitute an exhaustive list of all aspects of anyparticular embodiment(s). Rather, this brief summary simply presentsselected aspects of some example embodiments. It should be noted thatnothing herein should be construed as constituting an essential orindispensable element of any invention or embodiment. Rather, variousaspects of the disclosed embodiments may be combined in a variety ofways so as to define yet further embodiments. Such further embodimentsare considered as being within the scope of this disclosure.

As well, none of the embodiments embraced within the scope of thisdisclosure should be construed as resolving, or being limited to theresolution of, any particular problem(s). Nor should such embodiments beconstrued to implement, or be limited to implementation of, anyparticular technical effect(s) or solution(s).

The present disclosure is generally concerned with irrigation systems,such as pivot irrigation systems, for example, that include a continuoustrack transport system. In some embodiments, the continuous tracktransport system is configured to be backfit into already deployedirrigation systems that include tires, such as pneumatic tires. In otherembodiments, the continuous track system can be included as part of theinitial assembly of an irrigation system. In either case, the continuoustrack system can be substantially the same, that is, at least someembodiments of the continuous track system are equally well-suited to beinstalled at the time of initial construction or to be employed as abackfit installation. The continuous track system is particularlywell-suited for use in pivot irrigation systems, but the scope of theinvention is not limited to such irrigation systems, and the continuoustrack system can be used in any other irrigation system, or applicationsother than irrigation, where it may prove useful.

With continuing reference now to further example embodiments, it shouldbe understood that embodiments within the scope of this disclosure mayinclude any one or more of the following elements, and features ofelements, in any combination: a continuous track transport system; anirrigation system that includes a continuous track transport system; awheel-less or tire-less irrigation system; a continuous track transportsystem in the form of an after-market system that can be installed on anexisting irrigation system that includes a wheel or tire transportsystem; a pivot irrigation system that includes a continuous tracktransport system; a continuous track transport system that does notemploy tires or wheels; a continuous track transport system powered byan electric motor, or any other type of prime mover; a continuous tracktransport system that includes a power transmission gear train connectedto a continuous track with one or more drive wheels that are operable tocause movement of the track, and the power transmission gear train isconnectible to a prime mover; a prime mover for a continuous tracktransport system, where the prime mover may be remotely controllable; acontinuous track transport system that includes a gear train having oneor more gears connected with one or more other gears by a chain ortoothed belt that is made at least in part of metal and/or plastic; acontinuous track transport system that includes one or more drive gearsin the form of a plastic sprocket; a continuous track transport systemthat includes a gear train having one or more gears made substantially,or completely, of plastic; a continuous track transport system that isinterchangeable with one or more tires of an existing irrigation system;a continuous track transport system that can be installed on the samehubs of an existing irrigation system where tires were initiallyinstalled, or intended to be installed; a continuous track transportsystem configured to be mounted to a pair of hubs of an irrigationsystem, which may be a pivot irrigation system; a continuous tracktransport system which, when used by an irrigation system of a givenweight, makes an impression in soil that has relatively greater areathan the impression created by a pair of tires of the same irrigationsystem; a continuous track transport system which, for an irrigationsystem of a given weight, exerts a pressure on the soil that is lessthan that exerted by a pair of tires of the same irrigation system; acontinuous track transport system that includes one or more replaceablegrousers; a continuous track transport system that includes one or moreplastic grousers; a continuous track transport system that includes achain to which a plurality of grousers are attached; a continuous tracktransport system that includes a plastic chain to which one or moregrousers are attached; a continuous track transport system that includesa plastic chain to which one or more plastic grousers are attached; acontinuous track transport system with a chain, each link of the chainbeing integral with a respective grouser; a grouser, which may beplastic or metal, that includes one or more skids on each side tofacilitate consistent ground contact with the grouser; a continuoustrack transport system with a plastic chain, each link of the plasticchain being integral with a respective grouser; a continuous tracktransport system that defines a soil contact area that is at least aslong as a distance between two hub axes of the continuous tracktransport system; a continuous track transport system that defines asoil contact area which is substantially the same length as thecontinuous track transport system; a continuous track transport systemwith only a single soil contact portion; a continuous track transportsystem that defines a soil contact area, a substantial portion, or all,of which remains in contact with the soil at all times; a continuoustrack transport system that defines a soil contact area, where the soilcontact area remains substantially the same size at all times; acontinuous track transport system that defines a soil contact area thatis generally rectangular in shape; a continuous track transport systemthat defines a soil contact area that is in the range of about 400square inches to about 700 square inches; a continuous track transportsystem with an adjustable soil contact area; a continuous tracktransport system that includes an un-tensioned track having a pluralityof grousers; a continuous track transport system having a generallyrectangular outline; a continuous track transport system whose trackcreates a generally rectangularly shaped impression in soil, rather thana generally U-shaped impression created by one or more tires that couldbe used in place of the track, and the impression created by the trackis substantially shallower than the U-shaped impression; and, a housingfor a continuous track transport system, the housing can be removablyattached to a frame or other structure of the continuous track transportsystem, and the housing can be made of metal and/or plastic, and mayinclude one or more access panels.

With continuing reference now to further example embodiments, it shouldbe understood that embodiments within the scope of this disclosure mayinclude any one or more of the following elements, and features ofelements, in any combination: a continuous track transport system; aglass-filled nylon frame; a glass-filled sprocket/gear combination; aglass-filled nylon track plate; a drive gear made of a combination ofacetal and polytetrafluoroethylene (PTFE) (a synthetic fluoropolymer oftetrafluoroethylene); an acetal sprocket; a glass-filled nylon sprocket;a nylon hub; a plastic hub; an acetal hub bushing; a nylon rub rail; anda ductile iron hub with zinc chromate coating; a continuous tracktransport system that includes any combination of the foregoingcomponents; a pivot irrigation system that includes the foregoingcontinuous track transport system.

In connection with the present disclosure, acetal refers topolyoxymethylene (POM), which is an engineering thermoplastic. As well,nylon is used herein as a generic designation for a particular family ofsynthetic polymers, namely, aliphatic or semi-aromatic polyamides.

As well, this disclosure embraces the embodiments disclosed herein bothin respective assembled forms, and in respective kit forms. When in theform of a kit, the embodiment may be partly or completely disassembled,and the kit can be employed at the time of construction of an irrigationsystem, or as an after-market modification to an existing irrigationsystem.

Following is a non-exclusive list of embodiments within the scope of theinvention. It should be understood that aspects of the variousembodiments may be combined in other ways to define still furtherembodiments.

In a first example embodiment, a continuous track transport systemincludes a continuous track operably engaged with a pair of drivewheels, and each of the drive wheels is mounted, or mountable, to acorresponding hub of an irrigation system.

In a second example embodiment, a portion of an irrigation system has acontinuous track transport system which includes a continuous trackoperably engaged with one or more drive wheels, and each of the one ormore drive wheels is mounted, or mountable, to a corresponding hub ofthe portion of the irrigation system.

In a third example embodiment, a tower of a pivot irrigation system hasa continuous track transport system which includes a continuous trackoperably engaged with one or more drive wheels, and each of the one ormore drive wheels is mounted, or mountable, to a corresponding hub ofthe tower of the pivot irrigation system.

In a fourth example embodiment, a continuous track transport systemincludes a continuous track operably engaged with one or more drivewheels, where the one or more drive wheels are coupled to a drive motorby way of a gear train, and each of the one or more drive wheels ismounted, or mountable, to a corresponding hub of an irrigation system.

In a fifth example embodiment, a continuous track transport systemincludes a continuous track operably engaged with one or more drivewheels, where the one or more drive wheels are coupled to a drive motorby way of a gear train that includes one or more plastic gears and/orplastic sprockets, and each of the one or more drive wheels is mounted,or mountable, to a corresponding hub of an irrigation system.

In a sixth example embodiment, a continuous track transport systemincludes a continuous track operably engaged with one or more drivewheels, where the one or more drive wheels are coupled to a gear trainthat includes one or more gears, and where one of the gears or drivewheels is connected to another gear or drive wheel with a chain ortoothed belt, and each of the one or more drive wheels is mounted, ormountable, to a corresponding hub of an irrigation system.

In a seventh example embodiment, a continuous track transport systemincludes an un-tensioned track operably engaged with one or more drivewheels.

In an eighth example embodiment, a continuous track transport systemincludes a track having a chain with a plurality of links, each of thelinks having a respective grouser attached thereto, where one or more ofthe links and/or one or more of the grousers are plastic.

In a ninth example embodiment, a continuous track transport systemincludes a continuous track operably engaged with a pair of drivewheels, and each of the drive wheels is mounted, or mountable, to acorresponding hub of an irrigation system.

In a tenth example embodiment, a portion of an irrigation system has acontinuous track transport system which includes a continuous trackoperably engaged with one or more drive wheels, and each of the one ormore drive wheels is mounted, or mountable, to a corresponding hub ofthe portion of the irrigation system.

In an eleventh example embodiment, a tower of a pivot irrigation systemhas a continuous track transport system which includes a continuoustrack operably engaged with one or more drive wheels, and each of theone or more drive wheels is mounted, or mountable, to a correspondinghub of the tower of the pivot irrigation system.

In a twelfth example embodiment, a continuous track transport systemincludes a continuous track operably engaged with one or more drivewheels, where the one or more drive wheels are coupled to a drive motorby way of a gear train, and each of the one or more drive wheels ismounted, or mountable, to a corresponding hub of an irrigation system.

In a thirteenth example embodiment, a continuous track transport systemincludes a continuous track operably engaged with one or more drivewheels, where the one or more drive wheels are coupled to a drive motorby way of a gear train that includes one or more plastic gears and/orplastic sprockets, and each of the one or more drive wheels is mounted,or mountable, to a corresponding hub of an irrigation system.

In a fourteenth example embodiment, a continuous track transport systemincludes a continuous track operably engaged with one or more drivewheels, where the one or more drive wheels are coupled to a gear trainthat includes one or more gears, and where one of the gears or drivewheels is connected to another gear or drive wheel with a chain ortoothed belt, and each of the one or more drive wheels is mounted, ormountable, to a corresponding hub of an irrigation system.

In a fifteenth example embodiment, a continuous track transport systemincludes an un-tensioned track operably engaged with one or more drivewheels.

In a sixteenth example embodiment, a continuous track transport systemincludes a track having a chain with a plurality of links, each of thelinks having a respective grouser attached thereto, where one or more ofthe links and/or one or more of the grousers are plastic.

In a seventeenth example embodiment, a continuous track transport systemincludes a continuous track that includes a plurality of track platesconnected to each other, and the track plates are made of glass-fillednylon.

In an eighteenth example embodiment, a continuous track transport systemincludes a pair of sprocket/gear components, each of which is made ofglass-filled nylon.

In a nineteenth example embodiment, a continuous track transport systemincludes first and second frame portions made of glass-filled nylon.

In a twentieth example embodiment, a continuous track transport systemincludes a drive gear that is made of a blend of acetal and PTFE.

In a twenty-first example embodiment, a continuous track transportsystem includes a sprocket bushing and/or hub bushing made of acetal.

In a twenty-second example embodiment, a continuous track transportsystem includes a rub rail made of nylon.

In a twenty-third example embodiment, a continuous track transportsystem includes a hub made of ductile iron and coated with zincchromate, or the hub can be plastic or nylon.

In a twenty-fourth example embodiment, a continuous track transportincludes any combination of the components recited in the aforementionedseventh example embodiment.

In a twenty-fifth example embodiment, a continuous track transportincludes all the components recited in the aforementioned seventeenththrough twenty fourth example embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The appended drawings contain figures of some example embodiments tofurther clarify various aspects of the present disclosure. It will beappreciated that these drawings depict only some embodiments of thedisclosure and are not intended to limit its scope in any way. Thedisclosure will be described and explained with additional specificityand detail through the use of the accompanying drawings in which:

FIG. 1 is a schematic plan view of an arrangement of pivot irrigationsystems;

FIG. 2 discloses aspects of an example tower of a pivot irrigationsystem;

FIG. 3 discloses aspects of an example tower of a pivot irrigationsystem, where the tower includes a continuous track transport system;

FIG. 3a discloses aspects of an example housing for a continuous tracktransport system;

FIG. 3b discloses aspects of an example shield for a continuous tracktransport system;

FIG. 4 is a right side perspective view of an example continuous tracktransport system;

FIG. 5a is a left side perspective view of an example continuous tracktransport system;

FIG. 5b is a partial left side perspective view of an example continuoustrack transport system, with part of the frame removed for clarity;

FIG. 5c is a partial right side perspective view of an examplecontinuous track transport system, with the motor removed for clarity;

FIG. 5d is a partial section view of an example drive hub;

FIG. 5e is a partial section view of an example axle hub;

FIG. 6 is a top view of an example continuous track transport system;

FIG. 7 is a bottom view of an example continuous track transport system;

FIG. 8a is a side cutaway view showing an example interface between acontinuous track transport system and a chassis of an irrigation system;

FIG. 8b is a detail view of a portion of an example chain and grousers;

FIG. 8c is a detail view of an example chain with grousers attached;

FIG. 8d is a detail view showing an interface between two examplegrousers; and

FIG. 9 discloses a track created by a continuous track transport system.

FIG. 10 is an exploded view of another example continuous tracktransport system (CTTS);

FIG. 11 is an exploded view of another example continuous tracktransport system (CTTS);

FIGS. 12-13 are directed to an example drive shaft of a CTTS;

FIGS. 14-15 are directed to an example hub connectible to a drive shaftof a CTTS;

FIGS. 16-17 are directed to an example hub bushing usable with the hubof FIGS. 14-15;

FIGS. 18-19 are directed to an example frame portion of a CTTS;

FIGS. 20-21 are directed to an example sprocket bushing of a CTTS;

FIGS. 22-23 are directed to an example drive gear of a CTTS;

FIGS. 24-25 are directed to a gear guard of a CTTS;

FIGS. 26-27 are directed to an example sprocket-gear combination of aCTTS;

FIGS. 28-29 are directed to an example rub rail of a CTTS;

FIGS. 30-31 are directed to an example bushing;

FIGS. 32-33 are directed to an example hub connectible to the bushing ofFIGS. 30-31;

FIG. 34 is a perspective view of an example CTTS; and

FIGS. 35-40 are directed to an example track plate and cover of a CTTS.

DETAILED DESCRIPTION OF SOME EXAMPLE EMBODIMENTS

The present disclosure is generally concerned with irrigation systemsand components. More specifically, at least some embodiments of theinvention are concerned with an irrigation system, one example of whichis a pivot irrigation system, that includes a continuous track transportsystem that enables the irrigation system to move throughout a fieldwhile largely, or completely, avoiding one or more of the problemsassociated with the use of transport systems that rely primarily ontires or wheels for movement of an associated irrigation system.Embodiments of the invention can be employed in a wide variety ofapplications and, accordingly, the scope of the invention is not limitedto the example applications and structures disclosed herein.

A. Example Configuration and Operating Environment

With reference first to FIG. 1, details are provided concerning aspectsof an example operating environment for at least some embodiments of theinvention. In the example of FIG. 1, a pivot irrigation system 100 isindicated. In general, and as disclosed in more detail in FIG. 2, thepivot irrigation system 100 has a pivot arm 102 whose length “L” isdefined by multiple lengths of watering pipe connected end to end andsupported by a series of towers. The length “L” defines the radius of acircular area “A” that can be watered by nozzles 104 of the pivotirrigation system 100 as the pivot arm 102 rotates about a fixed point“B.” Water can be supplied to the pivot arm 102 by way of a supply line106 connected to a pump station 108 that communicates with a watersource (not shown). Depending upon the size of a field or area to bewatered, one or more pivot irrigation systems 100 may be provided.

With continued attention to FIG. 1, and directing attention now to FIG.2 as well, further details are provided concerning the example pivotirrigation system 100. As indicated there, the pivot irrigation system100 may include one or more towers 110, which can be constructed in theform of a metal framework. The towers 110 support the individual pipelengths 102 a and 102 b that form part of the length of the pivot arm102. Each of the pipe lengths 102 a and 102 b may be in fluidcommunication with one or more nozzles 112, which can be pendant nozzlesas indicated in FIG. 2, or any other type of nozzle. With continuedreference to FIG. 2, one or more of the towers 110 may include a chassis114 that is supported by a pair of tires 116. For at least the reasonsset forth elsewhere herein however, the use of tires, such as tires 116,in irrigation systems has proven to be problematic.

Accordingly, attention is directed now to FIG. 3, where detailsconcerning aspects of example embodiments of the invention are provided.The pivot irrigation system 200 may be similar, or identical, to thepivot irrigation system 100 except that instead of tires, such as tires116, the pivot irrigation system 200 includes a continuous tracktransport system (CTTS), one example of which is denoted at 300.

Some, none, or all portions of the CTTS and its components may be coatedwith paint or other materials. At least some of such materials may serveto help prevent, or reduce, rust and corrosion. Surface treatments andtextures may also be applied to portions of the CTTS.

Many of the elements employed in the foddering are constructed, eitherin whole or in part, of one or more metals. Suitable metals may includesteels such as stainless steel, aluminum, and aluminum alloys, althoughthe skilled person will understand that a variety of other metals may beemployed as well and the scope of the invention is not limited to theforegoing examples. Where metal is employed in the construction of acomponent, the metal elements may take one or more forms including, butnot limited to, square tube, rectangular tube, oval tube, polygonaltube, round tube, pipe, and solid, rather than tubular, forms of any ofthe foregoing. Metal elements can be extruded, forged, machined, or anyof the foregoing. As disclosed in more detail elsewhere herein,materials such as plastics and rubber can be used either alone or incombination with one or more metals, in the construction of elements ofthe CTTS.

In general, where employed as a backfit or aftermarket item, the CTTS300 can be readily attached to the chassis 202 using the hubs (notshown) to which the tires (see 116 in FIG. 2) were formerly mounted. Ofcourse, the CTTS 300 can alternatively be included as an element of thepivot irrigation system 200 at the time of construction of the pivotirrigation system 200. In either case, the CTTS 300 eliminates the needfor tires or wheels to transport the pivot irrigation system 200throughout a field.

With continued reference to FIG. 3, and directing attention briefly nowto FIG. 3a , at least some embodiments of a CTTS, such as the exampleCTTS 300, may include a housing 301. Among other things, the housing 301may help to prevent the entry of foreign matter and/or other materialsinto various components of the CTTS, such as the gear train (discussedbelow). As well, the housing 301 can provide components of the CTTS witha level of protection from environmental conditions such as sun andrain. The housing 301 can be made of any suitable materials, includingmetal and/or plastic, for example. As well, the housing 301 may beconfigured to be removably attached to a frame and/or other structure ofthe CTTS 300. In at least some embodiments, the housing 301 includes oneor more access panels 301 a to enable a user to access CTTS componentsdisposed within the housing 301 for maintenance, removal and/or repair.Further, the housing 301 may include one or more vents 301 b that enableair movement through the housing 301. Finally, in addition, or as analternative to, the access panel(s) 301 a, the housing 301 may include acover 301 c, which may be hinged, that a user can open so as to accessCTTS components that are disposed within the housing 301.

With continued reference to FIGS. 3 and 3 a, and directing attentionbriefly now to FIG. 3b , a shield 301 d may be provided that can be usedin addition, or as an alternative, to the housing 301. In general, theshield 301 d can cover all, or part, of the CTTS components, such as thegear train (discussed below) for example. In this way, the shield 301 dcan help prevent foreign material from entering the gear train and/orother components of the CTTS. The shield 301 d can be made of the sameor similar materials as the housing 301, although that is not required.As well, the shield 301 d can be removably attached to structural orother elements of the CTTS, with bolts or screws for example. In someembodiments, the shield 301 d may include one or more access panels 301e that enable a user to gain access to components of the CTTS forinspection, repair and/or replacement, for example.

B. Aspects of Some Example Embodiments Continuous Track

With continued attention to FIG. 3, and directing attention as well toFIGS. 4-7, further details are provided concerning the example CTTS 300.As indicated in those Figures, the CTTS 300 may include a continuoustrack 302 that comprises a plurality of track elements, which can takethe form of grousers 302 a, connected together in such a way that anangle between successive grousers 302 a is variable and enables one ormore portions of the track 302 to assume a curved configuration, asshown in FIGS. 4 and 5 for example. In general, the example CTTS 300 mayhave a generally rectangular outline and, as such, may have a relativelysmaller vertical dimension than triangular shaped drive systems.

In at least some embodiments, one or more of the grousers 302 a includeone or more cleats 302 b. The cleat(s) 302 b, when present, can help toimprove traction and soil contact of the continuous track 302 as itmoves over terrain. The cleats 302 b can be integrally formed withrespective grousers 302, permanently attached to respective grousers302, or may be removably attached to respective grousers 302 so that thecleats 302 b can be replaced when worn, or to suit operating conditions.For example, a grouser that is suitable for use in sandy soil may not bewell suited for use in clay soil.

The grousers 302 a and cleats 302 b can be made of any suitablematerial, examples of which include plastic, rubber, metal, or anycombination of these. Moreover, the grouser 302 a and its correspondingcleat 302 b can be the same material as each other, but that is notrequired. More generally, a cleat 302 b of any of the aforementionedmaterials can be employed together with a grouser 302 a made of any ofthese materials, and the scope of the invention is not limited to anyparticular material(s) or combination(s) thereof.

In some cases, the grousers 302 a can be made of recycled plastic,examples of which include, but are not limited to, theultra-high-molecular-weight polyethylene (UHMWPE) that is sold byQuadrant Plastics under the trade name ‘Tivar ECO.’ Such plastics mayalso be known as high-modulus polyethylene, (HMPE), or high-performancepolyethylene (HPPE). Other plastics, or non-plastic materials, canalternatively be used for the grousers 302 a.

Finally, it will be appreciated that a variety of different continuoustrack 302 configurations can be defined. Thus, aspects such as the size,shape, and number of the grousers 302 a can be selected as desired todefine a continuous track 302 of a desired configuration. Furtherdetails concerning example grousers and an associated chain arediscussed elsewhere herein.

C. Aspects of Some Example Embodiments—Gear Trains

As further indicated in the Figures, the CTTS 300 may include a geartrain 304, part or all of which can be disposed within an envelopedefined by the continuous track 302. As best shown in FIG. 6, the gears,discussed below, of the gear train 304 may all reside in substantiallythe same lateral plane so as to form a substantially linear gear trainconfiguration. This configuration is provided by example only however,and other embodiments may employ a non-linear gear train configuration.

In the example illustrated in FIGS. 4-7, the gear train 304 includes adrive gear 306, which can be plastic or metal, or a combination of thetwo. A prime mover 400, such as an electric motor for example, includesa hub 402 with a flange 402 a. The prime mover 400 may be provided aspart of the CTTS 300, or may be existing equipment on an irrigationsystem chassis to which the CTTS 300 is to be mounted. With reference toFIGS. 5d and 6 in particular, the drive gear 306 may be mounted, such asby bolting for example, to a flange 308 a of a drive hub 308. The drivehub 308 further includes a flange 308 b configured to be removablyattached, such as with bolts for example, to corresponding flange 402 aof the hub 402. In this way, the CTTS 300 can be readily attached to,and detached from, the prime mover 400.

The drive hub 308, in turn, is mounted to a shaft 310, which may have astepped configuration as shown in FIG. 5d . As discussed in furtherdetail below, the shaft 310 may fixed to a frame 500 (discussed below)in such a way that the drive hub 308 and, thus, the drive gear 306,rotates about the shaft 310. To this end, one or more bearings 312 maybe provided within the drive hub 308 to rotatably support the drive hub308 as it rotates about the shaft 310. In one embodiment, the bearings312 are double row tapered bearings configured to accept both axial andradial loading components. Other bearings may alternatively be employedhowever. In one particular embodiment, the shaft 310 is made ofhot-rolled steel, such as hot-rolled steel conforming to ASTM 1018,although other materials can alternatively be employed. As well, theshaft 310 may be about 2.25 inches in diameter, and about 7 inches long,although different dimensions for the shaft 310 outside diameter andlength can alternatively be implemented.

In addition to the drive gear 306, and with continued reference to FIGS.4-7, the example gear train 304 may include one or more transfer gears314 that engage the drive gear 306. The transfer gears 314 may besubstantially the same size and configuration as each other, and can besized such that a single (1) rotation of the drive gear 306 causes >1rotation of each of the transfer gears 314, although this configurationis provided by way of example only and is not intended to limit thescope of the invention.

The transfer gears 314 can be mounted to, and rotate about, respectiveshafts 316. One or both of the shafts 316 can be permanently, ordetachably, attached to the frame 500 (discussed below) such that theshaft 316 is fixed and the transfer gear 314 rotates about the fixedshaft 316. In one alternative arrangement, the shafts 316 can berotatably supported by the frame 500, such as by way of bearings forexample, so that the transfer gear 314 and shaft 316 rotate in unisonwith each other.

In one particular embodiment, one or both of the shafts 316 are made ofround carbon steel tube, such as carbon steel tube conforming to ASTMA-513—Type 5 (1026 DOM), although other materials can alternatively beemployed. One or both of the shafts 316 may be about 3.5 inches inoutside diameter, and about 4 inches long, although different dimensionsfor the shaft 316 outside diameter and length can alternatively beimplemented.

As well, in one particular example embodiment, one or more transfergears 314 are made of plastic. In this example embodiment, no bearingsare required since the plastic transfer gear 314 is self-lubricating asit rotates about the shaft 316. Among other things, this bearing-lessconfiguration eliminates a possible failure mechanism and maintenanceburden, and reduces the overall weight and cost of the gear train 304.One or both of the plastic transfer gears 314 may be paired with aspacer (not shown) situated between the transfer gear 314 and the frame500 to prevent rubbing of the transfer gear 314 on the frame 500. Inalternative to this arrangement, one or both of the transfer gears 314,which may or may not be plastic, includes a bearing (not shown) that hasbeen press fit into the transfer gear 314. This bearing can provideradial and/or axial support to the transfer gear 314 as the transfergear 314 rotates about the corresponding shaft 316.

With continuing reference FIGS. 4-7, and particular reference to FIG. 5e, the gear train 304 also includes one or more driven gears 318 thateach engage a respective transfer gear 314. As well, the driven gears318 are each connected to a respective drive wheel 320 such that aninput to the drive gear 306 is transferred to the driven gears 318 and,accordingly, causes a corresponding rotation of the drive wheels 320.

More specifically, an axle hub 322 is provided that includes a flange322 a to which the driven gear 318 and drive wheel 320 are bolted. Inthe example of FIG. 5e , the driven gear 318 and drive wheel 320 may bebolted to the left-hand side of the flange 322 a, and the right-handside of the flange 322 a may be bolted to a corresponding flange of achassis hub, as discussed elsewhere herein. In some embodiments, theaxle hub 322 is made of steel that conforms to ASTM 1020, although othersteels can alternatively be used. The axle hub 322, in turn, is mountedto a shaft 324, which may have a stepped configuration as shown in FIG.5e . In one particular embodiment, the shaft 324 is made of hot-rolledsteel, such as hot-rolled steel conforming to ASTM 1018, although othermaterials can alternatively be employed. One or both of the shafts 324may be about 2.25 inches in diameter, and about 7 inches long, althoughdifferent dimensions for the shaft diameter and length can alternativelybe implemented.

As discussed in further detail below, the shaft 324 may be fixed to aframe 500 (discussed below) in such a way that the axle hub 322 and,thus, the driven gear 318 and drive wheel 320, rotates about the shaft324. To this end, one or more bearings 326 may be provided within theaxle hub 322 to rotatably support the axle hub 322 as it rotates aboutthe shaft 324. In one embodiment, the bearings 326 are configured toaccept a radial loading component. Other bearings may alternatively beemployed however.

Because the drive wheels 320 are each engaged with the continuous track302 (see, e.g., FIG. 8b ), rotation of the drive wheels 320 causes acorresponding movement of the continuous track 302, namely, clockwise inthe example of FIGS. 5a-5c . In at least some embodiments, one or bothof the drive wheels 320 take the form of a sprocket. The sprocket can bemade of plastic and, in one particular example embodiment, is in therange of about 14 inches to about 18 inches in diameter, with athickness in a range of about ¾ of an inch to about 1¼ inches. In onemore particular example, the sprocket is about 16 inches in diameter,and about 1 inch thick. The foregoing are presented only by way ofexample however, and the scope of the invention is not limited to thesedimensions or associated aspect ratios. As in the case of the drivewheels 320, one or both of the driven gears 318 can be partly, orcompletely, made of plastic, although that is not required. Moregenerally, at least the diameter and/or size and number of teeth of anycombination of the gears in the gear train 304 can be varied as desiredto achieve a particular gear ratio and/or other effects.

As best shown in FIGS. 5a-5c , the design and configuration of the geartrain 304 is such that both of the transfer gears 314 and drive wheels320 rotate in the same direction, for a given output direction of thedrive gear 306. It can likewise be seen that a range of variations canbe implemented to the CTTS 300. Thus, in some embodiments, at least someof the gears of the drive train 304 can be omitted.

For example, the transfer gears 314 can both be omitted, and the drivegear 306 directly connected, or coupled by a chain or toothed belt forexample, to the driven gears 318. With this configuration, the CTTS 300will still implement a desired rotation of the drive wheels 320. Anotheraspect of this configuration is that the overall length of the geartrain 304 is shortened and this, in turn, can enable a relativelyshorter track 302 and correspondingly smaller soil contact area. Thissmaller soil contact area may be desirable where, for example, the CTTS300 is used with a relatively small tower.

As another example of a modification that could be made to the drivetrain 304, the driven gears 318 could be omitted, and the transfer gears314 each mounted to a respective axle hub 322, along with a respectivedrive wheel 320, and engaged directly, or by a chain or toothed belt,with the drive gear 306. In this arrangement, the direction of rotationof the drive wheels 320 would be opposite that indicated in FIGS. 5a-5c, assuming that the input provided by the drive gear 306 is the same asshown in FIGS. 5a -5 c.

In yet another modification to the drive train 304, one transfer gear314 and the associated driven gear 318 can be omitted, leaving only asingle transfer gear 314 and associated driven gear 318. In this examplearrangement, the input from the drive gear 306 is thus directed only toone of the drive wheels 320 and the other drive wheel 320 is onlyconnected to the drive gear 306 by way of the track 302.

While the foregoing example modifications to the gear train 304 concernthe omission of one or more gears, yet other modifications can be madeto the drive train 304 that involve the addition of one or more gears.For example, one or more gears can be added so as to effectivelyincrease the overall length of the gear train 304 and, correspondingly,the length of the track 302 and the soil contact area.

It will also be apparent from FIGS. 5-7 that a desired output rotationalspeed of the driven gears 318, transfer gears 314, and drive wheels 320can be obtained by selection of suitable gear sizes and arrangements ofgears. With reference to the illustrative example of CTTS 300, the drivegear 306 is larger in diameter than either of the transfer gears 314 andthe driven gears 318. Thus, a relatively low rotational speed input(which can be expressed as revolutions per minute, or RPM) to the drivegear 306 will result in a relatively higher rotational speed of thetransfer gears 314, driven gears 318 and drive wheels 320. In thisexample, the transfer gears 314 not only convert the rotational motionof the drive gear 306 to a rotational motion of the driven gears 318,but also increase the rotational speed of the driven gears 318 relativeto the rotational speed of the drive gear 306.

With the foregoing points in view, and with continued reference to FIGS.5a-5c and FIGS. 6-7, one particular example embodiment of the drivetrain 304 includes gears of various specific sizes. More particularly,in this example embodiment, a drive gear 306, two transfer gears 314 andtwo driven gears 318 are provided. In this example, the drive gear 306has a pitch diameter of about 16 inches and 32 teeth, the transfer gears314 have a pitch diameter of about 13 inches and 26 teeth, and thedriven gears 318 have a pitch diameter of about 8 inches and 16 teeth.The foregoing relations between pitch diameters and teeth can be used toselect gears of yet other pitch diameters and tooth counts. However, thescope of the invention is not limited to the foregoing example nor tothe foregoing relations and, accordingly, any other suitable gearconfigurations and relations can be employed.

As the foregoing discussion makes clear, movement of the continuoustrack 302 can be effected with a wide variety of different CTTS gearingarrangements and gear train configurations. Accordingly, the scope ofthe invention is not limited to the example arrangements andconfigurations disclosed herein.

In connection with the foregoing, it should be noted that any of thegears within the scope of this disclosure can be constructed of avariety of different materials. Thus, and in general, any of thedisclosed gears, in any combination, can be made of plastic, or metal,for example. That is, any combination of one or more of the drive gear306, transfer gears 314, driven gears 318, and drive wheels 320 may bemade of plastic, or metal. Moreover, a gear train may include plasticgears exclusively, or metal gears exclusively, or may include acombination of plastic gears and metal gears. Metals that can be used inthe construction of metal gears include, but are not limited to, steel,steel alloys, aluminum, and aluminum alloys.

In at least one embodiment, all the gears of the gear train are plastic.As discussed in more detail below, the plastic may be the same for eachgear, or different types of plastic may be used in two or more differentgears. Although, as discussed below, plastic gears may be advantageousin certain circumstances, they need not be used in all embodiments, orin any embodiment.

Lighter weight gear materials, such as plastic, for example, may beparticularly useful in at least some applications as such materials canhelp reduce the overall weight of the CTTS, and also reduce the loadimposed on the prime mover 400. Plastic gears may also be desirable dueto their resistance to rust, corrosion, galling, seizing and otherproblems that may sometimes be associated with the use of certain metalsand combinations of metals. Plastic gears may also be more weatherresistant than metal gears. For example, some embodiments of plasticgears may include an additive or other material(s) that make the plasticgear resistant to ultraviolet (UV) light.

As well, plastic gears are relatively light and inexpensive whencompared with steel gears of comparable dimensions and configurations.For example, some types of plastic are only about 1/7 the weight ofsteel. As well, plastic gears can be molded and thus avoid at least someprocesses, such as casting, for example, sometimes associated with theconstruction of metal gears. Moreover, any of the gears disclosedherein, whether plastic or metal, can include one or more lightningholes to achieve a further reduction in weight.

It should also be noted that where a gear train such as gear train 304includes more than one plastic gear, different plastics can be used fordifferent gears. For example, and with reference to two gears engagedwith each other, one of the gears may be made of a first type of plasticand the other of the two gears may be made of a second type of plasticthat is different from the first type of plastic. Depending upon theplastics selected, such a plastic-to-plastic engagement arrangement canenable a relative reduction in wear and friction as compared with anarrangement where both plastics are the same, or an arrangement whereone gear is plastic and the other gear is metal.

The disclosed plastic gears can be formed by any of a variety ofprocesses, or combinations of processes. Example production processesfor plastic gears include, but are not limited to, any one or more ofinjection molding, extrusion, rotational molding, and blow molding. Aswell, the plastic gears can be cut from stock and then machined usingmethods such as turning, milling, drilling, shaping, and hobbing. Avariety of factors can inform the design and production of the gears,whether made of plastic or other material(s). Examples of such factorsinclude weather, soil types, humidity, topography, desired weight of thegear train, cost, friction properties, and reliability.

With the foregoing in view, following is a brief discussion of exampleplastics that can be used in the construction of various components of agear train, one example of which is the gear train 304. For example, thedrive wheels, driven gears, drive gear, and skids, or any combination ofthe foregoing, can be made of the same type of plastic. One example ofsuch a plastic includes any plastic from the family of syntheticpolymers known generically as aliphatic polyamides, and sometimes soldunder the trade name ‘nylon.’

In a more particular example, an aliphatic polymide that contains finelydivided particles of molybdenum disulphide (MoS₂) may be especially wellsuited to some applications. One such plastic is sold by QuadrantPlastics under the trade name Nylatron® GSM. The presence of the MoS₂may serve to enhance the load bearing capabilities of this plastic,while maintaining the impact resistance that is characteristic ofaliphatic polymides.

Yet other components of one or more embodiments of a drive train may bemade of a different plastic. For example, the transfer gears may be madeof polyoxymethylene (POM). POM is a thermoplastic that can be used inparts that require high stiffness, low friction, and dimensionalstability. It should be noted that POM is sometimes referred to asacetal, polyacetal, or polyformaldehyde. As well, POM may be sold undertrade names such as Delrin, Celcon, Ramtal, Duracon and Hostaform, forexample.

As the foregoing makes clear, a variety of different plastics can beemployed in different embodiments of the invention. Accordingly, thescope of the invention is not limited to the use of any particularplastic, or combination of plastics.

D. Aspects of Some Example Embodiments Frame

With continued reference to FIGS. 4-7, at least some embodiments of theCTTS 300 include a frame 500. The frame 500 may include a support arm502 that supports respective shafts, discussed elsewhere herein, towhich the drive gear 306, transfer gears 314, and driven gears 318 aremounted, as shown in FIGS. 5a-5c for example. In general then, thesupport arm 502 may support shaft 310, one or more shafts 316, and oneor more shafts 324.

In at least some embodiments, the support arm 502 includes an array ofpre-formed holes that enable a user to define a desired gear train 304configuration. By way of example, the support arm 502 can include aplurality of openings, such as four or more, for example, which are eachconfigured to receive a shaft 324. In this way, a user can position ashaft 324 in a variety of different locations and thereby customize thegear train configuration 304 to suit a particular need or application.Additionally, or alternatively, and as illustrated by the example ofFIG. 5a , the support arm 502 can include one or more slots 502 b, whichcan be vertically, horizontally, or angularly, oriented. Such slots 502b enable a shaft to be slid into a desired location, thereby permittingready customization and/or adjustment of a drive train 304. Such slots502 b can include a plurality of cutouts 502 c configured to receive aportion of a shaft, where each of the cutouts 502 c defines a differentrespective shaft position. A locking bar not shown or other structure(s)can be used to retain a shaft in a particular cutout 502 c until it isdesired to remove the shaft from that cutout 502 c.

With continued reference to FIGS. 4-7, further details will now beprovided concerning the example frame 500. As shown in the Figures, aplurality of vertical support members 504 are connected to the supportarm 502. Each of the vertical support members 504 rests on a respectivecross-piece 506 that rests on a pair of parallel base members 508. One,some, or all of the support member 502, vertical support members 504,cross-pieces 506, and base members 508 may be in the form of tube orpipe, or may be in the form of a solid member. The various pieces andmembers of the frame 500 can be permanently, or removably, attached toeach other in any suitable manner, such as, but not limited to, bolting,welding, or brazing, or any combination of the foregoing.

In at least some embodiments, the support arm 502, the support members504, and/or the cross-pieces 506, or any combination of the foregoing,may be made of cold-formed carbon steel, such as the cold-formed carbonsteel conforming with the ASTM A 500 specification, although othermaterials can alternatively be employed. In one particular embodiment,the cross-pieces 506 are 2″×2″×12″ (long) square tube, although othersizes and configurations of materials can alternatively be used. In thesame embodiment, and/or in other embodiments, the support arm 502 is2″×6″×56″ (long) rectangular tube, although other sizes andconfigurations of materials can alternatively be used. In yet otherembodiments, one or more components of the frame 500, such as thesupport arm 502, for example, may be made of plastic, such as any of theplastics disclosed herein.

As best shown in FIGS. 4 and 5 a-5 c, some embodiments of the basemembers 508 are configured and arranged so that the base member 508serves as a rub rail for the grousers 352 (and/or 302 a) as the grousers352 move underneath the base member 508. As well, the contact piece 508a can serve as a chain guide that limits, or prevents, lateral movementof the chain 360 (discussed below). The contact piece 508 a may be madeof a relatively rigid material that can support the weight of the geartrain 304, but which is sufficiently soft that it does not cause unduewear on interior surfaces of the grousers 302 a that it contacts. Aswell, the material of the contact piece 508 a may be a relativelylow-friction material. Examples of such materials for the contact pieces508 a include, but are not limited to, solid fluorocarbons such aspolytetrafluoroethylene (PTFE) which may be sold under the Teflon® mark,and thermoplastics such as polyoxymethylene (POM) which may be soldunder the Delrin® mark.

E. Aspects of Some Example Embodiments Irrigation System Chassis

With reference briefly now to FIG. 8a , details are provided concerningan example interface between a system such as the CTTS 300 and a chassis600 of an irrigation system, such as a pivot irrigation system, forexample. The chassis 600 may be the same as, or similar to, chassis 114(see FIG. 2), or may have another configuration.

In the example of FIG. 8, the flanges 322 a of the axle hubs 322 of theCTTS 300, or another CTTS, are configured and arranged to be connectedwith corresponding chassis hubs 602 of the chassis 600. Moreparticularly, the flanges 322 a of the axle hubs 322 can be bolted, orotherwise attached, to flanges 602 a of the chassis hubs 602. As aresult of this configuration of the CTTS 300, it can be readily attachedto, and detached from, the existing hubs of an irrigation systemchassis. This configuration thus enables ready replacement of irrigationsystem tires with a CTTS, and also enables ready removal of the CTTSfrom the irrigation system chassis, should there be a need to do so. Ofcourse, the scope of the invention is not limited to the use of hubsand/or flanges. More generally, any other structure(s) that enable readyattachment and detachment of a CTTS to/from an irrigation system chassiscan alternatively be employed.

Turning now to FIGS. 8b-8d , details are provided concerning aparticular example of a grouser and chain configuration that can be usedin at least some embodiments. In the example of FIGS. 8b-8d , the trackis denoted generally at 350 and includes a chain 360 that engages adrive gear in the form of a sprocket 370. Example aspects of a sprocket,such as sprocket 370, are disclosed elsewhere herein. In generalhowever, the sprocket 370 may include a plurality of teeth 372 wheresuccessive teeth are separated by spaces 374 that successively engagecorresponding pins 362 of the chain 360. The pins 362 also securesuccessive links 364 of the chain 360 to each other. In the example ofFIGS. 8b-8d , the links 364 are metal, although that is not required. Inother embodiments, the links 364 can be plastic and connected to eachother with pins, which may be metal.

As best shown in FIG. 8b , each of the links 364 may define one or moreholes 364 a which can accommodate a respective fastener 366, such as abolt, screw or rivet for example, for releasably fastening a grouser 352to the link 364. As indicated in FIG. 8d , the configuration andarrangement of the grousers 352 and links 364 is such that adjacentgrousers 352 can change their angular position relative to each other.

In at least one example embodiment, the links 364 and grousers 352 mayboth be plastic. In yet another example embodiment, the links 364 andgrousers 352 can be integrally formed with each other. That is, a link364 and associated grouser 352 may take the form of a single piece ofmaterial, such as plastic, for example, and the links 364 joined to eachother with metal or plastic pins.

F. Operational Aspects of Some Example Embodiments

In general, the operation of a CTTS is similar to tires in that the CTTSis able to transport an irrigation system through a field. However, andwith attention finally to FIG. 9, it can be seen that the CTTS mayresolve a number of problems typically associated with the use of tiresin irrigation systems such as pivot irrigation systems.

In particular, and as indicated in FIG. 9, it can be seen that aconventional tire 700 of an irrigation system creates a relatively wideand deep track 702 profile in the soil. The creation of such tracks 702is problematic for reasons stated elsewhere herein. Moreover, thepressure exerted by the tire(s) 700 on the soil is relatively largebecause the contact area 704 between the tire 700 and soil is relativelysmall.

In contrast, a continuous track 800, such as may be used in embodimentsof a CTTS, creates a relatively wide, but shallow, track 802 in thesoil. For at least the reasons explained elsewhere herein, the track 802is significantly less problematic than the track 702. This track 802profile is at least partly a result of the fact that the pressureexerted on the soil by the continuous track 800 is relatively low, atleast in comparison with the tire 700 which is typically employed onmany irrigation systems. The low pressure is, in turn, a function of therelatively large contact area 804 between the continuous track 800 andthe soil.

G. Operational Aspects of Some Example Embodiments

With reference to FIGS. 4-7 and 9, example embodiments of the CTTSoperate generally as described hereafter. In particular, an input torqueapplied to a drive gear, such as drive gear 306, by a prime mover, suchas prime mover 400, causes operation of a gear train, such as gear train304. Operation of the gear train causes the rotation of a pair of drivewheels, such as drive wheels 320, which in turn, causes the rotation ofa continuous track, such as continuous track 302, that is connected tothe drive wheels. The motion of the continuous track causes the movementof an associated portion of an irrigation system through a field. As theirrigation system moves through the field, a track profile, such as thetrack 802, may be created. In some instances, the soil and fieldconditions may be such that a very small, or no, track is created by theCTTS.

H. Useful Aspects of Some Example Embodiments

As will be apparent from the disclosure, one or more embodiments of theCTTS can provide one or more advantageous and unexpected effects, in anycombination, some examples of which are set forth below. It should benoted that such effects enumerated herein are neither intended, norshould be construed, to limit the scope of the claimed invention in anyway.

One useful aspect of some embodiments of the invention is that suchembodiments do not create the wide and deep tracks that commonly resultfrom the use of tires or wheels on movable irrigation systems.Consequently, the soil erosion and related problems typically associatedwith the use of such tires or wheels may be reduced, or avoided, by useof a CTTS.

Another useful aspect of some embodiments of the invention is that themaintenance and cost burdens associated with the use of tires and wheelsmay be reduced, or eliminated by the employment of a CTTS.

I. Aspects of Further Example Embodiments

With reference next to FIGS. 10 and 11, two further embodiments 1000 and1200, respectively, of a CTTS are disclosed. It should be noted that,with regard to any embodiment disclosed herein, reference to a ‘unified,single-piece structure’ or variations thereof, embraces moldedstructures, among other things, although none of the structuresdisclosed herein are required to be molded. Moreover, where a structureis molded, any suitable molding process or processes can be used, andthe scope of the invention is not limited in that regard.

As well, it should also be noted that any of the components of theembodiments disclosed in FIGS. 11-40 may comprise, or consist of,glass-filled nylon. The glass-filled nylon components can be molded, orotherwise formed. Likewise, any of the components of the embodimentsdisclosed in FIGS. 1-10 may comprise, or consist of, glass-filled nylon.The glass-filled nylon components can be molded, or otherwise formed.Glass-filled nylon is one, non-limiting, example of a non-metallicmaterial that can be used for any of the components disclosed herein.

As indicated in the particular example of FIG. 11, the CTTS can includetwo frame portions 1202 that cooperate to contain and support variousother components. In at least some embodiments, the frame portions 1202are made of glass-filled nylon, although other materials couldalternatively be used. Further structural details of the frame portionsare set forth in FIGS. 18 and 19. In general, operation of the CTTS 1000and 1200 can be similar, or identical, to the CTTS embodiments disclosedin the '555 Application incorporated herein.

Within the frame portions 1202, a pair of sprocket-gears 1204 areprovided that are configured to engage a drive gear 1206. In at leastsome embodiments, the sprocket-gears 1204 include a plurality of teeth1204 a and are made of glass-filled nylon, although other materialscould alternatively be used. Further structural details of thesprocket-gears 1204 are set forth in FIGS. 26 and 27. In at least someinstances, the sprocket-gear 1204 has a unified, single-piece structure.A gear guard 1205 helps to protect the sprocket-gears 1204 and drivegear 1206 from foreign matter. The gear guard 1205 can be made of metal,plastic, or other suitable material. Further structural details of thegear guard 1205 are disclosed in FIGS. 24 and 25.

With continued reference to the Figures, the sprocket-gears 1204 areconfigured to engage the track 1208, such as by way of the recesses 1204b, such that when driven by the drive gear 1206, the sprocket-gears 1204impart motion to the track 1208 which includes a plurality of trackplates 1209 connected to each other and which releasably engage therecesses 1204 b. The drive gear 1206 can be made of a blend of acetaland PTFE, although other materials could alternatively be used. Furtherstructural details of the drive gear 1206 are set forth in FIGS. 22 and23. The track plates 1209 can be made of glass-filled nylon, althoughother materials could alternatively be used. Further structural detailsof the track plates 1209 are set forth in FIGS. 32-38. In at least someembodiments, each track plate 1209 takes the form of a unified singlepiece structure. The sprocket-gears 1204 are rotatably supported bysprocket bushings 1210, which can be made of acetal.

The CTTS 1200 further includes a pair of rub rails 1212 that can protectthe frame portions 1202 from rubbing by the track 1208. The rub rails1212 can be made of nylon, although other materials could alternativelybe used. Further structural details of the rub rails 1212 are set forthin FIGS. 28 and 29. The rub rails 1212 may define an internal channel1212 a, and may also include one or more flexible portions 1212 b. Theflexible portions 1212 b may be created through the use of a number oflateral cuts or other structures or features in the portion which isdesired to be made flexible.

On the front of the CTTS 1200, a bushing 1214 and hub 1216 are providedthat are able to connect with, and support, the drive gear 1206. Thebushing 1214 can be made of steel or acetal, and the hub 1216 of ductileiron, and coated with zinc chromate. Other materials for the bushing1214 and/or hub 1216 could alternatively be used. Further structuraldetails of the bushing 1214 and hub 1216 are set forth in FIGS. 30-31,and FIGS. 32-33, respectively.

On the other side of the CTTS 1200, a drive shaft 1218 is provided thatmay be made of steel, or other suitable material(s). Further structuraldetails of the drive shaft 1218 are set forth in FIGS. 12 and 13. Thedrive shaft 1218 is connectible by way of fasteners 1217 to a hub 1220that is supported in the frame portion 1202 by a hub bushing 1222.Similar to the hub 1216, the hub 1220 can be made of ductile iron, andcoated with zinc chromate, although other materials could alternativelybe used for the hub 1220 material and/or coating. Further structuraldetails of the hub 1220 are set forth in FIGS. 14 and 15. The hubbushing 1222 can be made of steel, or other suitable material(s).Further structural details of the hub 1220 are set forth in FIGS. 16 and17.

With reference finally to FIGS. 34-40, various views of an example trackplate 1209 are indicated. As best shown in FIGS. 34, 35, 36, 39 and 40,each of the track plates 1209 can include engagement structures 1209 aand 1209 b on respective sides of the track plate 1209. Thus, successivetrack plates 1209 can be joined together by sliding the engagementstructure 1209 b of a first track plate 1209 into the engagementstructure 1209 a of the adjacent track plate 1209. In this way, thetrack 1208 can have a continuous structure.

With particular reference to FIG. 35, the top side of each track plate1209 can include a crossbar 1209 c. The crossbar 1209 c is configuredand arranged to be removably received in a notch 1204 b (see FIG. 26) ofa sprocket-gear 1204. In this way, rotation of the sprocket-gears 1204causes movement of the track 1208.

As indicated in FIGS. 37-40, each of the track plates 1209 can include acover 1226. The track plates 1209 can define a recess 1209 d to whichthe cover 1226 can be attached, such as by way of fasteners 1228. Thecover 1226 is intended to be permanently installed. The recess 1209 d iscreated as part of a molding process for the track plate 1209. Withoutthe recess 1209 d, the area of the track plate 1209 in the vicinity ofthe recess 1209 d may be too thick and not inject, or cool, consistentwith the rest of the track plate 1209. The cover 1226 covers the recess1209 d to keep the track plate 209 from carrying dirt and/or otherforeign matter.

Although this disclosure has been described in terms of certain exampleembodiments, other embodiments apparent to those of ordinary skill inthe art are also within the scope of this disclosure.

What is claimed is:
 1. A continuous track transport system (CTTS)suitable for use in connection with an irrigation system, comprising: acontinuous track that includes a plurality of track plates configuredand arranged so that adjacent track plates are directly connected toeach other; a gear train, comprising: a drive gear configured andarranged to receive a rotary input by way of an interface that isconnectible to a portion of an irrigation system chassis; and first andsecond driven sprocket-gears engaged with the continuous track, each ofthe first and second driven sprocket-gears including a respective drivengear engaged with the drive gear to enable transfer of the rotary inputfrom the drive gear to the first and second driven sprocket-gears; and aframe which rotatably supports one or more gears of the gear train. 2.The CTTS as recited in claim 1, wherein the track plates compriseglass-filled nylon.
 3. The CTTS as recited in claim 1, wherein the drivegear comprises acetal and PTFE.
 4. The CTTS as recited in claim 1,wherein the frame comprises glass-filled nylon.
 5. The CTTS as recitedin claim 1, further comprising a hub connected at least indirectly tothe drive gear, the hub comprising either: plastic; or, ductile iron andhaving a zinc chromate coating on at least a portion of the hub.
 6. TheCTTS as recited in claim 1, further comprising a rub rail engaged withan edge of the frame, the rub rail comprising nylon.
 7. The CTTS asrecited in claim 1, wherein the plurality of track plates includes firstand second adjacent track plates comprising respective first and secondcomplementary structures that are rotatably engaged with each other. 8.The CTTS as recited in claim 1, wherein the driven gears of the firstand second driven sprocket-gears are integral with the first and seconddriven sprocket-gears, respectively.
 9. The CTTS as recited in claim 1,wherein the drive gear and/or the first and second driven sprocket-gearscomprise glass-filled nylon.
 10. A continuous track transport system(CTTS) suitable for use in connection with an irrigation system,comprising: a continuous track that includes a plurality of track platesconfigured and arranged so that adjacent plates are directly rotatablyconnected to each other, and the track plates each comprise glass-fillednylon; a gear train operable to transmit an input torque to thecontinuous track to effect movement of the continuous track, the geartrain including: a drive gear configured and arranged to receive theinput torque by way of an interface that is connectible to an irrigationsystem chassis; first and second driven sprocket-gears engaged with thecontinuous track, each of the first and second driven sprocket-gearsincluding a respective driven gear engaged with the drive gear, and thefirst and second driven sprocket-gears each comprise glass-filled nylon;and a frame which rotatably supports one or more gears of the geartrain.
 11. The CTTS as recited in claim 10, further comprising a hubconnected at least indirectly to the drive gear, the hub comprisingeither: plastic; or, ductile iron and having a zinc chromate coating onat least a portion of the hub.
 12. The CTTS as recited in claim 10,wherein the drive gear comprises acetal and PTFE.
 13. The CTTS asrecited in claim 10, wherein one or both of the first and second drivensprocket-gears is in the form of a unified, single piece structure. 14.The CTTS as recited in claim 10, wherein the frame comprises first andsecond frame portions between which a portion of the gear train isdisposed, and the first and second frame portions each compriseglass-filled nylon.
 15. A continuous track transport system (CTTS)suitable for use in connection with an irrigation system, comprising: acontinuous track that includes a plurality of track plates configuredand arranged so that adjacent plates are directly connected to eachother; a gear train operable to transmit an input torque to thecontinuous track to effect movement of the continuous track, the geartrain including: a drive gear configured and arranged to receive theinput torque by way of an interface that is connectible to an irrigationsystem chassis; and first and second driven sprocket-gears engaged withthe continuous track, and each of the first and second drivensprocket-gears including a respective driven gear that is engaged withthe drive gear, wherein the first and second driven sprocket-gearscomprise glass-filled nylon and are each formed as a respective unified,single piece structure; and a frame which rotatably supports one or moregears of the gear train.
 16. The CTTS as recited in claim 15, whereinthe frame comprises first and second frame portions between which aportion of the gear train is disposed.
 17. The CTTS as recited in claim15, wherein the interface comprises a drive shaft, and the CTTS furthercomprises a hub that is connected to the drive shaft and supported inthe frame by a hub bushing.
 18. The CTTS as recited in claim 15, furthercomprising a hub 1216 connected to the drive gear and supported in theframe by a bushing.
 19. The CTTS as recited in claim 15, wherein thedrive gear comprises acetal and PTFE.
 20. The CTTS as recited in claim15, wherein the drive gear is positioned between the first and seconddriven sprocket-gears.
 21. The CTTS as recited in claim 15, furthercomprising a pair of rub rails engaged with an edge of the frame, therub rails each comprising nylon.
 22. The CTTS as recited in claim 15,further comprising a gear guard disposed within the frame and configuredand arranged to help prevent ingress of foreign matter to thesprocket-gears and the drive gear.